A thin-film transistor liquid crystal display (TFT-LCD) has the advantages of small volume, low power consumption, non-radiation, etc. and has prevailed in the current flat panel display market. As for the TFT-LCD, the product performance, the yield and the price of the TFT-LCD are determined by a structure and a manufacturing process of an array substrate.
Currently, the array substrate is manufactured by using many patterning processes. In order to effectively reduce the price of the TFT-LCD and improve the yield of the TFT-LCD, the manufacturing process of the array substrate is gradually simplified, that is, from the original seven patterning processes to four patterning processes based on the gray-tone mask technology. The current four patterning processes technology utilizes a gray-tone or half-tone mask to finish the patterning of an active layer, a data line, a source electrode, a drain electrode and a channel region for a thin-film transistor (TFT) by one patterning process.
As each patterning process generally includes photoresist coating, exposure, development, etching, striping and other processes, the number of the patterning processes can be used for measuring the complexity of the manufacturing process of the array substrate. In the manufacturing process of the array substrate, the fewer the number of the patterning processes adopted is, the shorter the production time is, the higher the production efficiency is, the lower the manufacturing cost is.